SanDisk already looking beyond flash memory

Company believes that flash memory will max out during the next decade.

SanDisk sees flash memory maxing out during the next decade and believes 3D technology is the answer.

A model of stacked Toshiba transistors
A model of stacked Toshiba transistors Michael Kanellos

Flash memory disk supplier SanDisk said this week that it is looking beyond flash memory because of anticipated limitations. SanDisk intends to tap into 3D read-write memory technology it acquired with the purchase of Matrix Semiconductor back in 2005.

3D memory chips can store more data vertically, allowing greater densities. While conventional integrated circuits put all active circuitry on the silicon substrate, SanDisk's 3D architecture deposits multiple layers of active memory elements so that circuitry extends vertically as well.

Speaking at this week's second-quarter earnings conference call, Sanjay Mehrotra, SanDisk president and chief operating officer, said his company is "developing the 3D read/write memory that we believe will replace NAND flash sometime in the next decade when it can no longer be economically scaled."

SanDisk 3D technology uses multi-layered three dimensional integrated circuits SanDisk

This follows a Securities and Exchange Commission disclosure earlier in the quarter covering an agreement that SanDisk signed with Toshiba to collaborate on the development of rewriteable 3D memory. SanDisk and Toshiba "will jointly perform research and development" on 3D memory, the companies said in the disclosure.

SanDisk has made progress with the technology since it acquired Matrix, according to Chairman and CEO Eli Harari, speaking earlier this week duing the earnings conference call. "SanDisk has been making good, steady progress since our acquisition three years ago of Matrix Semiconductor...We currently have more than 200 issued patents that cover key elements of 3D rewritable memory technology," Harari said.

Based on these statements and its collaboration with Toshiba, SanDisk believes 3D memory, though challenging, is a viable successor to flash. Commercialization presents "significant challenges" but the "effort is worth the prize as 3D memory is a potential game changer," Harari said. The technology would "achieve the cost structure to disrupt hard disk drive in the coming decade," he said.

Relatively little is known about what SanDisk has achieved with Matrix's 3D technology. The company currently sells a product that uses 3D technology but the device can only be programmed once: that is, it is not rewritable.

But more is known about Toshiba's technology, which is rewritable. The long, thin yellow poles in the 3D transistor model pictured above are silicon piers. The piers control the flow of electrons, boosting performance.

SanDisk spokesperson Michael Wong added that SanDisk has a long way to go extending flash memory technology before it makes the leap to 3D. The company will begin production of "X3" technology this year that stores three bits per memory cell and plans on moving to X4 (four bits) in 2009.